Andrew's git - gitweb.git/blob

   1#!/bin/sh
   2#
   3# Copyright (c) 2005 Junio C Hamano
   4#
   5
   6USAGE='[-n] [--no-commit] [--squash] [-s <strategy>] [--reflog-action=<action>] [-m=<merge-message>] <commit>+'
   7
   8. git-sh-setup
   9
  10LF='
  11'
  12
  13all_strategies='recur recursive octopus resolve stupid ours'
  14default_twohead_strategies='recursive'
  15default_octopus_strategies='octopus'
  16no_trivial_merge_strategies='ours'
  17use_strategies=
  18
  19index_merge=t
  20
  21dropsave() {
  22        rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
  23                 "$GIT_DIR/MERGE_SAVE" || exit 1
  24}
  25
  26savestate() {
  27        # Stash away any local modifications.
  28        git-diff-index -z --name-only $head |
  29        cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
  30}
  31
  32restorestate() {
  33        if test -f "$GIT_DIR/MERGE_SAVE"
  34        then
  35                git reset --hard $head
  36                cpio -iuv <"$GIT_DIR/MERGE_SAVE"
  37                git-update-index --refresh >/dev/null
  38        fi
  39}
  40
  41finish_up_to_date () {
  42        case "$squash" in
  43        t)
  44                echo "$1 (nothing to squash)" ;;
  45        '')
  46                echo "$1" ;;
  47        esac
  48        dropsave
  49}
  50
  51squash_message () {
  52        echo Squashed commit of the following:
  53        echo
  54        git-log --no-merges ^"$head" $remote
  55}
  56
  57finish () {
  58        if test '' = "$2"
  59        then
  60                rlogm="$rloga"
  61        else
  62                echo "$2"
  63                rlogm="$rloga: $2"
  64        fi
  65        case "$squash" in
  66        t)
  67                echo "Squash commit -- not updating HEAD"
  68                squash_message >"$GIT_DIR/SQUASH_MSG"
  69                ;;
  70        '')
  71                case "$merge_msg" in
  72                '')
  73                        echo "No merge message -- not updating HEAD"
  74                        ;;
  75                *)
  76                        git-update-ref -m "$rlogm" HEAD "$1" "$head" || exit 1
  77                        ;;
  78                esac
  79                ;;
  80        esac
  81        case "$1" in
  82        '')
  83                ;;
  84        ?*)
  85                case "$no_summary" in
  86                '')
  87                        git-diff-tree --stat --summary -M "$head" "$1"
  88                        ;;
  89                esac
  90                ;;
  91        esac
  92}
  93
  94case "$#" in 0) usage ;; esac
  95
  96rloga= have_message=
  97while case "$#" in 0) break ;; esac
  98do
  99        case "$1" in
 100        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
 101                --no-summa|--no-summar|--no-summary)
 102                no_summary=t ;;
 103        --sq|--squ|--squa|--squas|--squash)
 104                squash=t no_commit=t ;;
 105        --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
 106                no_commit=t ;;
 107        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
 108                --strateg=*|--strategy=*|\
 109        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
 110                case "$#,$1" in
 111                *,*=*)
 112                        strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
 113                1,*)
 114                        usage ;;
 115                *)
 116                        strategy="$2"
 117                        shift ;;
 118                esac
 119                case " $all_strategies " in
 120                *" $strategy "*)
 121                        use_strategies="$use_strategies$strategy " ;;
 122                *)
 123                        die "available strategies are: $all_strategies" ;;
 124                esac
 125                ;;
 126        --reflog-action=*)
 127                rloga=`expr "z$1" : 'z-[^=]*=\(.*\)'`
 128                ;;
 129        -m=*|--m=*|--me=*|--mes=*|--mess=*|--messa=*|--messag=*|--message=*)
 130                merge_msg=`expr "z$1" : 'z-[^=]*=\(.*\)'`
 131                have_message=t
 132                ;;
 133        -m|--m|--me|--mes|--mess|--messa|--messag|--message)
 134                shift
 135                case "$#" in
 136                1)      usage ;;
 137                esac
 138                merge_msg="$1"
 139                have_message=t
 140                ;;
 141        -*)     usage ;;
 142        *)      break ;;
 143        esac
 144        shift
 145done
 146
 147# This could be traditional "merge <msg> HEAD <commit>..."  and the
 148# way we can tell it is to see if the second token is HEAD, but some
 149# people might have misused the interface and used a committish that
 150# is the same as HEAD there instead.  Traditional format never would
 151# have "-m" so it is an additional safety measure to check for it.
 152
 153if test -z "$have_message" &&
 154        second_token=$(git-rev-parse --verify "$2^0" 2>/dev/null) &&
 155        head_commit=$(git-rev-parse --verify "HEAD" 2>/dev/null) &&
 156        test "$second_token" = "$head_commit"
 157then
 158        merge_msg="$1"
 159        shift
 160        head_arg="$1"
 161        shift
 162elif ! git-rev-parse --verify HEAD >/dev/null 2>&1
 163then
 164        # If the merged head is a valid one there is no reason to
 165        # forbid "git merge" into a branch yet to be born.  We do
 166        # the same for "git pull".
 167        if test 1 -ne $#
 168        then
 169                echo >&2 "Can merge only exactly one commit into empty head"
 170                exit 1
 171        fi
 172
 173        rh=$(git rev-parse --verify "$1^0") ||
 174                die "$1 - not something we can merge"
 175
 176        git-update-ref -m "initial pull" HEAD "$rh" "" &&
 177        git-read-tree --reset -u HEAD
 178        exit
 179
 180else
 181        # We are invoked directly as the first-class UI.
 182        head_arg=HEAD
 183
 184        # All the rest are the commits being merged; prepare
 185        # the standard merge summary message to be appended to
 186        # the given message.  If remote is invalid we will die
 187        # later in the common codepath so we discard the error
 188        # in this loop.
 189        merge_name=$(for remote
 190                do
 191                        rh=$(git-rev-parse --verify "$remote"^0 2>/dev/null) &&
 192                        if git show-ref -q --verify "refs/heads/$remote"
 193                        then
 194                                what=branch
 195                        else
 196                                what=commit
 197                        fi &&
 198                        echo "$rh               $what '$remote'"
 199                done | git-fmt-merge-msg
 200        )
 201        merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name"
 202fi
 203head=$(git-rev-parse --verify "$head_arg"^0) || usage
 204
 205# All the rest are remote heads
 206test "$#" = 0 && usage ;# we need at least one remote head.
 207test "$rloga" = '' && rloga="merge: $@"
 208
 209remoteheads=
 210for remote
 211do
 212        remotehead=$(git-rev-parse --verify "$remote"^0 2>/dev/null) ||
 213            die "$remote - not something we can merge"
 214        remoteheads="${remoteheads}$remotehead "
 215done
 216set x $remoteheads ; shift
 217
 218case "$use_strategies" in
 219'')
 220        case "$#" in
 221        1)
 222                use_strategies="$default_twohead_strategies" ;;
 223        *)
 224                use_strategies="$default_octopus_strategies" ;;
 225        esac
 226        ;;
 227esac
 228
 229for s in $use_strategies
 230do
 231        case " $s " in
 232        *" $no_trivial_merge_strategies "*)
 233                index_merge=f
 234                break
 235                ;;
 236        esac
 237done
 238
 239case "$#" in
 2401)
 241        common=$(git-merge-base --all $head "$@")
 242        ;;
 243*)
 244        common=$(git-show-branch --merge-base $head "$@")
 245        ;;
 246esac
 247echo "$head" >"$GIT_DIR/ORIG_HEAD"
 248
 249case "$index_merge,$#,$common,$no_commit" in
 250f,*)
 251        # We've been told not to try anything clever.  Skip to real merge.
 252        ;;
 253?,*,'',*)
 254        # No common ancestors found. We need a real merge.
 255        ;;
 256?,1,"$1",*)
 257        # If head can reach all the merge then we are up to date.
 258        # but first the most common case of merging one remote.
 259        finish_up_to_date "Already up-to-date."
 260        exit 0
 261        ;;
 262?,1,"$head",*)
 263        # Again the most common case of merging one remote.
 264        echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
 265        git-update-index --refresh 2>/dev/null
 266        new_head=$(git-rev-parse --verify "$1^0") &&
 267        git-read-tree -u -v -m $head "$new_head" &&
 268        finish "$new_head" "Fast forward"
 269        dropsave
 270        exit 0
 271        ;;
 272?,1,?*"$LF"?*,*)
 273        # We are not doing octopus and not fast forward.  Need a
 274        # real merge.
 275        ;;
 276?,1,*,)
 277        # We are not doing octopus, not fast forward, and have only
 278        # one common.  See if it is really trivial.
 279        git var GIT_COMMITTER_IDENT >/dev/null || exit
 280
 281        echo "Trying really trivial in-index merge..."
 282        git-update-index --refresh 2>/dev/null
 283        if git-read-tree --trivial -m -u -v $common $head "$1" &&
 284           result_tree=$(git-write-tree)
 285        then
 286            echo "Wonderful."
 287            result_commit=$(
 288                echo "$merge_msg" |
 289                git-commit-tree $result_tree -p HEAD -p "$1"
 290            ) || exit
 291            finish "$result_commit" "In-index merge"
 292            dropsave
 293            exit 0
 294        fi
 295        echo "Nope."
 296        ;;
 297*)
 298        # An octopus.  If we can reach all the remote we are up to date.
 299        up_to_date=t
 300        for remote
 301        do
 302                common_one=$(git-merge-base --all $head $remote)
 303                if test "$common_one" != "$remote"
 304                then
 305                        up_to_date=f
 306                        break
 307                fi
 308        done
 309        if test "$up_to_date" = t
 310        then
 311                finish_up_to_date "Already up-to-date. Yeeah!"
 312                exit 0
 313        fi
 314        ;;
 315esac
 316
 317# We are going to make a new commit.
 318git var GIT_COMMITTER_IDENT >/dev/null || exit
 319
 320# At this point, we need a real merge.  No matter what strategy
 321# we use, it would operate on the index, possibly affecting the
 322# working tree, and when resolved cleanly, have the desired tree
 323# in the index -- this means that the index must be in sync with
 324# the $head commit.  The strategies are responsible to ensure this.
 325
 326case "$use_strategies" in
 327?*' '?*)
 328    # Stash away the local changes so that we can try more than one.
 329    savestate
 330    single_strategy=no
 331    ;;
 332*)
 333    rm -f "$GIT_DIR/MERGE_SAVE"
 334    single_strategy=yes
 335    ;;
 336esac
 337
 338result_tree= best_cnt=-1 best_strategy= wt_strategy=
 339merge_was_ok=
 340for strategy in $use_strategies
 341do
 342    test "$wt_strategy" = '' || {
 343        echo "Rewinding the tree to pristine..."
 344        restorestate
 345    }
 346    case "$single_strategy" in
 347    no)
 348        echo "Trying merge strategy $strategy..."
 349        ;;
 350    esac
 351
 352    # Remember which strategy left the state in the working tree
 353    wt_strategy=$strategy
 354
 355    git-merge-$strategy $common -- "$head_arg" "$@"
 356    exit=$?
 357    if test "$no_commit" = t && test "$exit" = 0
 358    then
 359        merge_was_ok=t
 360        exit=1 ;# pretend it left conflicts.
 361    fi
 362
 363    test "$exit" = 0 || {
 364
 365        # The backend exits with 1 when conflicts are left to be resolved,
 366        # with 2 when it does not handle the given merge at all.
 367
 368        if test "$exit" -eq 1
 369        then
 370            cnt=`{
 371                git-diff-files --name-only
 372                git-ls-files --unmerged
 373            } | wc -l`
 374            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 375            then
 376                best_strategy=$strategy
 377                best_cnt=$cnt
 378            fi
 379        fi
 380        continue
 381    }
 382
 383    # Automerge succeeded.
 384    result_tree=$(git-write-tree) && break
 385done
 386
 387# If we have a resulting tree, that means the strategy module
 388# auto resolved the merge cleanly.
 389if test '' != "$result_tree"
 390then
 391    parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
 392    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 393    finish "$result_commit" "Merge made by $wt_strategy."
 394    dropsave
 395    exit 0
 396fi
 397
 398# Pick the result from the best strategy and have the user fix it up.
 399case "$best_strategy" in
 400'')
 401        restorestate
 402        echo >&2 "No merge strategy handled the merge."
 403        exit 2
 404        ;;
 405"$wt_strategy")
 406        # We already have its result in the working tree.
 407        ;;
 408*)
 409        echo "Rewinding the tree to pristine..."
 410        restorestate
 411        echo "Using the $best_strategy to prepare resolving by hand."
 412        git-merge-$best_strategy $common -- "$head_arg" "$@"
 413        ;;
 414esac
 415
 416if test "$squash" = t
 417then
 418        finish
 419else
 420        for remote
 421        do
 422                echo $remote
 423        done >"$GIT_DIR/MERGE_HEAD"
 424        echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
 425fi
 426
 427if test "$merge_was_ok" = t
 428then
 429        echo >&2 \
 430        "Automatic merge went well; stopped before committing as requested"
 431        exit 0
 432else
 433        {
 434            echo '
 435Conflicts:
 436'
 437                git ls-files --unmerged |
 438                sed -e 's/^[^   ]*      /       /' |
 439                uniq
 440        } >>"$GIT_DIR/MERGE_MSG"
 441        if test -d "$GIT_DIR/rr-cache"
 442        then
 443                git-rerere
 444        fi
 445        die "Automatic merge failed; fix conflicts and then commit the result."
 446fi